Well, there they are, the four prototypes:

I played around a bit with connectivity options. So two PiDPs use a Raspberry Pi Model A+, the other two a Model B+. The machine in front has a slot on top to access the HDMI monitor connector (slot not necessary with the right HDMI cable, BTW), the other machines only run terminals from serial or network terminals which is all you need.

• The Model A's have the serial port enabled (meaning R23&24 were clipped off from the Pi's).
  • To connect a modern laptop, use a USB-to-TTL-Serial cable. A neat plug & play solution without need for a power supply: the PiDP runs happily off its 5V power pin.
  • To hook up a vintage serial terminal, you need a TTL Serial-to-RS232 converter, and a 5V power supply (or a laptop's USB port).
• All PiDPs have a micro WiFi adapter plugged in, so you can log in to PDP terminals that way too - or use WiFi with VNC to run the Pi's desktop GUI concurrent with the PDP-8 terminal...

My better half has decided that our suitcases will be filled with more important things than PiDPs on the way back home from VCF East. Like shoes, I presume. So if you're at the VCF and want to take one of these PiDPs, please let me know :) They are 100% compatible with the future final version of the board, they just have some manual fixes on the PCB.